Social predictor Companies who want to know more about prospective employees can learn a lot by checking their Facebook profiles, according to a new study.

Jennifer Golbeck and colleagues at the University of Maryland surveyed the public profiles of nearly 300 Facebook users for information about their favourite activities, TV shows, movies, music, books, quotes, and membership in political or other organisations.

They also looked at the "About Me" and "blurb" sections. The work did not include status updates or other data that is only available to users' online friends.

The researchers then had users take a test that measures the "big five" personality traits: openness to experience, conscientiousness, extroversion, agreeableness and neuroticism.

"It turns out you can get to within 10 per cent of a person's personality score by looking at Facebook," says Golbeck, a computer science professor who has become an expert at social media studies.

"Lots of organisations make their employees take personality tests. If you can guess someone's personality pretty well on the Web you don't need them to take the test."

People who tested as "extroverts" on the personality test tended to have more friends, but their networks tended to be more sparse, meaning that they made friends with lots of different people who are less likely to know each other.

The researchers also found that people with long last names tended to be more neurotic, perhaps because "a lifetime of having one's long last name misspelled may lead to a person expressing more anxiety and quickness to anger," according to the study, which is being presented this week at the Computer Human Interaction conference in Vancouver.

The Facebook-personality study also found that women were found to be significantly more conscientious, agreeable, as well as neurotic than men.

Golbeck, who co-directs the Human-Computer Interaction Lab at Maryland, says that gauging a person's personality is important to how well they will get along with others in school or a job.

"Do neurotic people get along, or do neurotic people seek out people who are calmer and more conscientious," says Golbeck. "If we can better understand people's relationships with one another, who they will trust online, potentially we can understand who they should interact with."

Sam Gosling, a psychology professor at the University of Texas , says some things can't be measured in these kinds of studies, such as a person's values, attitudes, identity and beliefs.

"The big five are just behavioural traits. There are deeper things like that aren't captured and are hard to measure."

Despite these drawbacks, Gosling says social media is providing a new window on studying human behaviour and personality.

"It is very important to know what other people are like," says Gosling. "Huge professional or personal decisions are based on what other people are like. It's important to use the best information we can."

Golbeck's study was funded in part by the Army Research Laboratory, which is interested in how teams of individuals get along to accomplish difficult tasks in the battlefield. Her next project: comparing Twitter posts to the big five exam.

"The correlations are stronger," says Golbeck. "Twitter is going to give us more information on personality."